3. Olber’s Paradox

4. The universe is expanding!

5. Hubbles Law

8. Cosmic Microwave Background (CMB) Large Scale Structure
Four Main Issues
Cosmic Microwave Background (CMB)
Large Scale Structure
Universal Acceleration
Gravitational Leaks

15. Sachs-Wolfe effect

16. DARK MATTER:
Gravity from baryons alone could not account for fluctuations.
The ratios of the power spectrum peaks indicate relative dark matter density.
Dark matter comprises 25% of the critical density.

17. Acceleration
Has the universe always been accelerating?
If not, when did it start, and what is causing it?

19. Repulsive Gravity? Matter and Energy produce gravity.
The amount (density) of matter and energy in the universe determines the rate that it will slow down.
GR allows for repulsive energies (Dark Energy)

20. As the universe expands, the matter density decreases.
The dark energy density remains the same. Or does it…?

21. GENERAL RELATIVITY NEEDS FIXING
There are theories suggesting that:
DARK ENERGY INCREASES
DARK ENERGY DECREASES
GENERAL RELATIVITY NEEDS FIXING

22. The dominant fix today is string theory: